SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
SEC Schedule, 12-09, Reserve, Impairment of Recognized Servicing Asset [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense		$ 8,523		$ 388,068	$ 263,817
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction		544,351	[1]	96,518	13,017	[1]
SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount		6,881		542,709	251,159		$ 359
allowance for uncollectible notes [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Financing Receivable, Allowance for Credit Loss, Noncurrent					0		44,038
Increase (Decrease) in Notes Receivables	[1]				0
Increase (Decrease) in Accounts and Notes Receivable					44,038
SEC Schedule, 12-09, Allowance, Credit Loss [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense		3,209		1,276	1,108
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	[1]	114		23	170
SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount		$ 7,476		$ 4,381	$ 3,128		$ 2,190

[1] For allowance for uncollectible notes, deductions represent reversals of allowances due to the collection of amounts owed. For allowance for doubtful accounts, deductions represent the write-off of accounts receivable deemed uncollectible. For allowance for expirations of unproved crude oil and natural gas properties, deductions represent actual expired or abandoned unproved crude oil and natural gas properties, with a corresponding decrease to the historical cost of the associated asset.